Dear Folks,
With slurpd, copying a tree from one slave to another was like this:
1. stop slapd on both slaves.
2. netcat the directory across from one slave to the other.
3. stop slurpd on master
4. edit slurpd.status to make the time and replication number match
by copying that for the source to that for the destination slave.
5. start everything back up.
My question with syncrepl is:
How do I copy the database for a tree from one consumer to another
consumer (of the same producer) so that the newly copied replica knows
where its replication should continue from?
Is the state for replication of the database stored in the contextCSN
of the suffix entry?
If so, does that mean that with syncrepl, the above operation is
reduced to the following three steps?
1. Stop slapd on both consumers.
2. Netcat the database from one to the other.
3. start both consumers.

The procedures you described would only have worked in the past if all of the
servers had identical architecture. The only supported means for copying
databases is using slapcat and slapadd, which use LDIF and are
architecture-independent. There is no need to stop the first consumer when
running slapcat.